Peace talks in Nigeria between the Sudanese government and Darfur's two main rebel groups have ended without any progress, amid ongoing fighting.

The fourth round of African Union-brokered negotiations ended Tuesday in Abuja after 11 days without any discussions on political issues.

Instead, rebels and government negotiators accused each other of violating an existing April cease-fire.

But after meeting with Nigerian President Olusegun Obasanjo, the two sides agreed to return to Abuja for more talks on a date in January 2005 to be confirmed later.

They also promised to halt the fighting to create a conducive environment for the next round.

A spokesman for one of the rebel groups, Ahmed Tugod, expressed satisfaction with the outcome, saying it's what rebels have been asking for ever since the talks opened.

"The Sudan government should stop immediately all their military activities on the ground and withdraw to their original positions and then after that people will come back to the talks in the next round," he said.

The head of Sudan's government delegation, Majzoud al-Khalida Ahmed, welcomed the efforts by the African Union, and accused rebels of not taking the talks seriously.

"We came here with a very high delegation with six ministers but unfortunately the leaders of the movements are not here," he said. "They are out fighting, they are not coming. They are trying to take the Darfur case out of Africa because they don't trust Africans."

Following reports of the start of a major government offensive in Darfur last week, rebels asked for the matter to be discussed urgently at the U.N. Security Council.

Human rights groups have called for peacekeepers and more observers on the ground in Darfur. So far, there are just 800 African Union monitors.

Fighting in Sudan's western region between mainly black African rebels and Arab-led troops and militias started in early 2003. Tens of thousands of people have been killed and more than two million others severely affected.